Non-leaf Nodes

Non-leaf nodes, which can have children, provide the framework through which this data is accessed and organized. They are of complex types.

There are two major types of non-leaf nodes (aside from a root node, which is a special case):

• Sequence group nodes, which provide organizational grouping for purposes such as repetition. In XSD, they are of complexType of a sequence of elements.

• Choice group nodes, which represent sets of alternatives— only one of which is valid at any given time for an instance of that node. For example, a choice node named order might have two children, respectively named domestic and overseas. For each order instance, only one of these children will be present. In XSD, they are of complexType of a choice group of elements.